. .
Page 3 of 14 FirstFirst 1234513 ... LastLast
  1. #21
    Would this be suitable for the transformer? https://cpc.farnell.com/multicomp/mc...%20transformer
    Is that all I would need?

    You will have to forgive my ignorance as I have an nane fear of magic blue smoke.

    Can you suggest any suitable drivers preferably available in the UK? I did find these https://www.cnc4you.co.uk/Microstepp...tepping-CW8060

    I will be using the existing 5 and 24V transformers.to power the bb-e

  2. #22
    Quote Originally Posted by dazp1976 View Post
    If I did it again I would get drivers that are rated upto 80Vac/110vdc and use a 70Vac toroidal transformer.
    Something like a 2*35vac secondary outputs wired in series for 70vac.
    Doesn't matter wether you have Nema 17/ 23/ 34size motors etc, the drivers regulate output voltage to the motors themselves.
    That's WRONG information your giving out, the drives don't regulate the voltage they regulate the current. 70Vac which is 98Vdc would destroy those little motors in no time at all. It would also make them run like a bag of shite.

    You cannot stick any voltage you like into a stepper, there is a limit where it starts to have very negative affects. Namely iron losses and motor heating which kills them.

    Those Large voltage Ac drives are only really any good for larger steppers Like Nema 34 or very high inductance NEMA 23's. Your typical 3-4Nm 4.2a Nema 23 with 3-4mh inductance doesn't like to be run much more than 80vdc and at that, you are pushing them past there design threshold so are shortening there life.

    For the NEMA 23 motors, which this machine will have fitted he'll only need drives with a max rating of 70Vdc and would run them around 55-60Vdc. Or 50Vac drives running at 40-45Vac.

  3. #23
    Quote Originally Posted by JAZZCNC View Post
    That's WRONG information .......
    Thanks - obviously reducing the power I supply will also reduce the initial outlay (as well as havingto replace everything including burnt oout motors).

    Could you be so kind as to point me in the right direction for what you would suggest and is there ay advantage with a toroidal transformer (a plug and play box suits me if possible).

    Although I have asked elsewhere on this forum have you any reasons why I shouldn't use the AXBB-E motion controller?

  4. #24
    whoops post twice
    Last edited by ngwagwa; 07-04-2020 at 04:40 PM. Reason: cok up

  5. #25
    Quote Originally Posted by ngwagwa View Post
    Would this be suitable for the transformer? https://cpc.farnell.com/multicomp/mc...%20transformer
    Is that all I would need?

    You will have to forgive my ignorance as I have an nane fear of magic blue smoke.

    Can you suggest any suitable drivers preferably available in the UK? I did find these https://www.cnc4you.co.uk/Microstepp...tepping-CW8060

    I will be using the existing 5 and 24V transformers.to power the bb-e
    My advise is STOP don't buy a single thing until you have settled on exactly what your fitting or need. Also what you have in the machine already that you can re-use.

    Those drives are a little over kill but that won't hurt, however, the advice you have been given regards the drives controlling Voltage is Wrong so ignore it.
    Those little motors won't like being run much above 60Vdc so the extra capacity the drives allow you cannot really use, but it's always better to have drives that are under performing than being pushed to there limits.

    Regards the transformer then the voltage is about right at 35V giving approx 50Vdc when rectified but the Va rating is a little on the low side, 500Va would be better. 300Va would work for those motors but doesn't leave any room for expansion or larger motors in the future 500Va would.

    When you say you have 5 and 24v in the machine are you sure it's DC because if it's the original PSU then they tend to be AC transformer and it gets rectified on the boards for the drives to around 32V.

  6. #26
    Hi,

    There is a 5v and a 24v transformer which I think are DC (I did take pictures but have left my phone in the workshop), I assume they were fitted when the machine was converted to Mach3 they are certainly not part of the original controller.

    My spindle is controlled by a plugin and serial port which I am happy to leave as is.

    I would prefer to purchase a PSU as opposed to building one unless there is an advantage going the toroidal route. Regarding your comment on the 300Va being sufficient but no room for expansion could I fit bigger motors if I needed to or would I need to if the new set up get the most out f the current ones?

    As to using what I can I was assuming that with a new motion controller, PSU and drives apart from the 5 & 24V transformers everything else would be redundant bar the mains on/off switch.

  7. #27
    Quote Originally Posted by ngwagwa View Post
    Thanks - obviously reducing the power I supply will also reduce the initial outlay (as well as havingto replace everything including burnt oout motors).
    Think I've just answered this one in last post but sorry you need larger not smaller for the reason stated below.

    Quote Originally Posted by ngwagwa View Post
    Could you be so kind as to point me in the right direction for what you would suggest and is there ay advantage with a toroidal transformer (a plug and play box suits me if possible).
    Ok well the advantage with toroidal transformer, when used with capacitors and bridge rectifiers that make up a DC PSU, (yes you need these as well) is that it means you can get away with lower power rating than you would need with a switch-mode supply. You can also build to the exact power requirements you need.

    It gets complicated but in a nutshell, let us say you have 4 motors all pulling 4a which means you'd need a 16a for a SWM supply to work reliably and keep up with drives/motors demands when working hard. In practice, the actual rating needed will be higher for reasons I won't get into now. But all this means a Large SWM PSU this size gets expensive quickly.

    Whereas a Toroidal/capacitor-based PSU allows you to get away with PSU size only 60% of the motors total draw. It does this by drawing from its bank of capacitors and how the drives work. It also ensures a smoother flow of power because you always have a reserve in the capacitors.
    So again, in a Nutshell, yes it's best for these reasons and the fact can size to exact needs and it's often much Cheaper when higher power is needed which is why it's used so much on routers and DIY builds.


    Regards the AXBB-E Controller I have never used one personally so I'm not recommending you use it but I do know several people who have used them and are very happy with them. I've fitted several of its Big brother the Uc300ETH and they are also very good so I cannot see these being a bad card. The UCCNC software is also very good so I wouldn't hesitate if it was me.

  8. #28
    Quote Originally Posted by ngwagwa View Post
    There is a 5v and a 24v transformer which I think are DC (I did take pictures but have left my phone in the workshop), I assume they were fitted when the machine was converted to Mach3 they are certainly not part of the original controller..
    Ok if that is the case then your sorted. It would be a good idea to post picturs of inside the control box.

    Quote Originally Posted by ngwagwa View Post
    My spindle is controlled by a plugin and serial port which I am happy to leave as is.
    If you go with the AXBB and UcCNC software then you won't be able to use it and I would use the UcCNC software over Mach3 as it's getting long in the tooth.

    Quote Originally Posted by ngwagwa View Post
    I would prefer to purchase a PSU as opposed to building one unless there is an advantage going the toroidal route.
    Ok well in that case look for a Unregulated Linear Supply. Gary at Zapp automation used to sell 48Vdc Leadshine Unreg PSU's give him a lookup.

    Quote Originally Posted by ngwagwa View Post
    Regarding your comment on the 300Va being sufficient but no room for expansion could I fit bigger motors if I needed to or would I need to if the new set up get the most out f the current ones?
    With 300Va then no you would need more current and 300Va limits you to about 8.5A total which could be borderline with some motors, with the current ones you probably won't have any trouble. But if one dies on you then you'll struggle to get the same size and it would be the ideal time to upgrade and 300Va would limit this.



    Quote Originally Posted by ngwagwa View Post
    As to using what I can I was assuming that with a new motion controller, PSU and drives apart from the 5 & 24V transformers everything else would be redundant bar the mains on/off switch.
    Ermm not really you will still want some safety involved so a few relays will be needed for a hardwired latching E-stop system that safely Kills drives etc and lets the controller know there's been an emergency Stop.

  9. #29
    Doddy's Avatar
    Lives in Preston, United Kingdom. Last Activity: 18 Hours Ago Has been a member for 8-9 years. Has a total post count of 1,330. Received thanks 185 times, giving thanks to others 63 times. Referred 1 members to the community.
    ngawagwa: Jazz offers some good advice but you still have the problem that down-time is costing you money. From what I read you're still in the "misbehaving" stage and trying to get going? The original Denford electronics were, I understand 24VAC (and only 100VA for the drivers), but you say that somewhere along the line someone has replaced a bunch of stuff with a Mach3 conversion - including a separate 24VDC PSU. It's possible that they've pushed this straight onto the existing Denford card (it is likely to just rectify/smooth this straight onto the drivers and this would work with DC).

    I offer the following cautiously, because it's a poor half-way house. If you need to try to get going quickly and don't mind a bit of down time to re-wire, then your original idea of slaving the DIV-268 onto the X-Axis could be sensible - and I can gift you a 200VA/36V SMPS. Yes, it's entirely the wrong PSU, but for a single axis (to test that the concept is right and you that have nothing else going wrong) it could get you going for the very short term. I can even drop you a couple more DIV-268s if they're handy for you (they are not great, but at 36V will out-perform the Denford drivers). That would just be to solidify you're own view as to what your shopping list needs to be and possibly get you back cutting tomorrow (if you don't remember my name - if you recall the vacuum bed? - I'm local). The PSU did, once upon a time, control a Denford star mill.

    It's absolutely not an end-solution - I'd agree with the previous sentiments that you need to throw 300-500VA at around 50V at this with a toroid. Your final choice of drivers may allow you a simple direct connection to a transformer (if they support AC supply) and a modern digital driver will outperform the old shite analogues (and I include the DIV-268s amongst those). And you'd need to weigh up the down-time of slaving an axis onto a separate PSU and driver (an hour?) against your productivity. But the offers there.

  10. #30
    I will getthe photos tomorrow.

    And never thought about the E-stop either but there is at least one relay in there :)

Page 3 of 14 FirstFirst 1234513 ... LastLast

Thread Information

Users Browsing this Thread

There are currently 2 users browsing this thread. (0 members and 2 guests)

Similar Threads

  1. Losing steps
    By Edendale in forum General Discussion
    Replies: 11
    Last Post: 06-03-2020, 09:10 PM
  2. Weird noise on travel and losing position
    By ngwagwa in forum Artsoft Mach (3 & 4)
    Replies: 12
    Last Post: 07-02-2020, 04:45 PM
  3. Router losing steps. Solution needed. Will this help?
    By cncbobuk in forum Chinese Machines
    Replies: 9
    Last Post: 27-12-2017, 02:40 AM
  4. Losing steps on Z axis
    By Arzo10 in forum Machine Discussion
    Replies: 15
    Last Post: 31-03-2017, 09:49 AM
  5. New Mill losing steps
    By lukecnc2012 in forum Gantry/Router Machines & Building
    Replies: 42
    Last Post: 08-11-2014, 01:56 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •